Deep Space TT&C Equipments of YH-1

A new upsurge of deep space exploration has arisen internationally during the 21th century. The TT&C (Tracking, Telemetry, Control ) technologies of deep space are very important. The YH-1 microsatellite is the first deep space explorer of China. In this article, the deep space TT&C characteristics, the key technologies of the YH-1 TT&C sub-system are introduced. The configuration and technical performance are provided concisely. The functions of TT&C for YH-1 microsatellite are: the telemetry link (downlink: from the microsatellite to the ground station) that transmits engineering data (spacecraft and instrument health and status measurements) and science data (including image data); the telecommand link (uplink: from the ground station to the microsatellite) that transmits the control information and commands to the microsatellite. The orbit parameters can be measured by one-way tracking, one-way Doppler frequency and VLBI. The microsatellite TT&C is working of X-band. In order to simplify the TT&C sub-system of the microsatellite, a transmitter and a receiver are used, instead of a transponder. The TT&C equipments onboard are designed with redundancy, which total weight is about 10kg.